In cell cultivation cells are introduced into culture flasks containing a nutritive medium where they grow, depending on the respective type of cell, either adherently, i.e. on the surface of the culture flask, or non-adherently, i.e. in a suspension in the nutritive medium. For harvesting and the continuing cultivation of non-adherently growing cells it has so far been common to concentrate the cells by centrifuging after the growth phase and before the further processing. There is the problem, however, that centrifuging gives rise to an undesirable aggregation of cells and to the occurrence of damage to the cells. Moreover, the manipulation involves a high risk of contamination by bacteria and fungi.
In the technique of co-culturing two cell species so far common mobile inserts are used which are equipped with a liquid-permeable but not cell-permeable membrane, which are placed into culture dishes for separating them into two cell compartments. The known inserts in culture disks, however, permit only the co-cultivation of two cell species only at a small scale and with different conditions only because one cell species is in the tissue culture dish whilst the other one is placed on the membrane. It is moreover inexpedient that the exchange of the culturing medium, the collection of the excess culture quantity and the repeated adjustment of the cell concentration is not possible or possible only within narrow limits.
From the document WO 96/00780 a cell culture apparatus subdivided into compartments is known wherein the cell compartment is defined by a lower gas-permeable membrane and by an upper membrane permeable to the nutritive medium so as to allow for a better supply of the cells with a simultaneous concentration of the macromolecular cell products in the cell compartment. Even though this cell culture apparatus allows for an exchange of the cell culture medium without centrifugation it does not permit harvesting of the macromolecular cell products without a subsequent separation of the cells by centrifuging. Apart therefrom, a co-culture of two cell species is not possible with such an apparatus.